/*#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
void fan(int s[], char a[], int n)
{
	int i;
	for (i = 0; i < n; i++)
		s[i] = a[n - i-1] - '0';
}
int main()
{
	char a[200] = { 0 }, b[200] = { 0 };
	int x[200] = { 0 }, y[200] = { 0 };
	int sum[200] = { 0 };
	while (scanf("%s%s", a, b) != EOF)
	{
		int c1, c2,i;
		c1 = strlen(a);
		c2 = strlen(b);
		fan(x, a, c1);
		fan(y, b, c2);
		for (i = 0; i < c1; i++)
		{
			if (x[i] >= y[i])
				sum[i] = x[i] - y[i];
			else
			{
				sum[i] = x[i] + 10 - y[i];
				x[i + 1] -= 1;
			}
		}
		for (i = c1 - 1; i >= 0; i--)
			printf("%d", sum[i]);
		printf("\n");
	}
	return 0;
}*/